This invention relates generally to a system for the production of a plasma. More particularly, the invention is directed towards a system for focusing and concentrating a laser beam onto a plasma-forming material in order to produce a plasma. The system is useful in the production of a plasma by laser radiation onto a target pellet of plasma-forming material.
Of the many proposed solutions to the continually growing need for energy, controlled thermonuclear reactors are a potential and perhaps one of the more prominent proposed solutions to the long-term energy problem. One area of interest in controlled thermonuclear reactor research is the investigation of the potential for laser-fusion. In this technique, thermonuclear fusion would be induced in a small pellet of deuterium and/or tritium containing material by irradiating it with an intense, coherent and, preferably, spherically and radially symmetric pulse of light from a laser. While the general theoretical process of inducing fusion by means of a laser is well-known and described in the prior art, briefly stated, the energy of a sufficiently intense pulse of laser light focused onto the surface of the target pellet is absorbed by the surface of the pellet, causing the surface to vaporize and expand away from the center of the pellet at high velocity. The reaction force from this expansion compresses the remainder of the pellet to high density, and the combined effect of the irradiation and compression heats the resultant plasma to a high temperature. When the combination of time, temperature and density of the compressed plasma is sufficiently large, the so induced fusion reaction of the deuterium and/or tritium will generate more energy than was required to compress the pellet and induce the fusion, permitting the generation of power.
While the feasibility of laser-fusion has yet to be conclusively demonstrated, considerable interest is being directed to this technique. Necessary research in this area involves the study of plasmas as well as the study of the compression of target pellets by an incident laser beam and the plasmas so produced. The particular aspect of this technique with which the present invention is concerned is a method and system which provides especially effective focusing of the laser beam onto a target pellet to produce a plasma.
It is an object of the present invention to provide a system for the production of a plasma.
It is another object of the present invention to provide a system in which a laser supplies an incident beam which is focused onto a plasma-forming material so as to produce a plasma.
An additional object of the present invention is to provide a system for the production of a plasma by irradiating a target pellet of a plasma-forming material by focusing a beam emitted by a laser onto the target material.
A further object of the present invention is to focus the incident laser beam in such a way that such a pellet plasma-forming material is irradiated with a high degree of radial and spherical symmetry.